Joining multiple tables across multiple data sources in MYSQL throws error

Question

Hi all,
I have to join tables across multiples MYSQL databases
eg :
Table T1,T2 from DB1
Table T3 from DB2
Columns from T3 are aggregated ( dimensional column ).
Hence when i query using oracle answers ( say i have columns from T1,T2 and T3 ) , OBIEE tries to a query DB1 by having NULL for columns in T3
It uses cast(NULL as INTEGER ) for columns from T3 . But MYSQL throws an error because "cast(NULL as INTEGER )" is not supported by MYSQL.
I tried executing the query generated by OBIEE manually , if i try giving cast(NULL as SIGNED INTEGER ) , it works.
pasting the query for reference
select distinct D1.c2 as c1,
D1.c1 as c2,
cast(NULL as INTEGER ) as c3
from
(select distinct T87.title_id as c1,
T59.asin as c2
from
print_book_catalog T59 left outer join
title_authority T87 On T59.asin = T87.asin
where ( T59.asin = '0345378911' )
) D1
I am not able to find any config file to set this property ( and use signed integer instead of integer ) . Even DBFeatures.INI does not have relevant information.
Can someobody please help me solve this problem.

Answer 1

Stijn,
Thank you for the article link. That was very helpful! It seems that I had a few things off as you do need the "This source should be combined with other sources at this level." checked. In my two table source columns for DATA_SOURCE I defined a literal ('086496' and '085597' for the other) in the Column Mapping tab. I pasted the following in the Fragmentation content, checking the "This source..." box on the Content tab:
eSIS.SANDBOX4_SCHOOLS.DATA_SOURCE = '086496'
And pasted the following into the WHERE clause, checking "Select distinct values" on the Content tab:
sandbox4."".OBIEE.NWOCA_SCHOOLS.SCHOOL_CODE = VALUEOF(NQ_SESSION."SCHOOL") AND sandbox4."".OBIEE.NWOCA_SCHOOLS.DATA_SOURCE = VALUEOF(NQ_SESSION."GROUP")
This took care of my user's security, utilizing the session variables in the WHERE clause. I am now able to generate reports that only one user can access from one data source and share that same report with another user who can only see data from the other data source.
Many thanks!!!